1. Field of the Invention
The present invention relates to a vacuum brake booster assembly for automotive vehicles.
2. Description of the Prior Art
The majority of vacuum brake boosters have the inherent problem that the dead stroke, i.e. the movement of the brake pedal experienced by the vehicle driver before any braking force is produced, is unacceptably long. Various modifications and methods of adjustment have been proposed to reduce the dead stroke. However in many cases a limited dead stroke remains which is attributable to the distance, in the rest position of the assembly, between the end of the booster output rod and the adjacent end of the master cylinder piston. This dead stroke arises from the need to take into account the maximum possible combination of manufacturing tolerances for both the master cylinder and the booster in order to be sure that the push rod does not touch the master cylinder piston when assembled and in the rest position.